Why? Lowest noise, beautiful viewfinder, it's quite fast, feels good... yeah. And it even has a video mode. *OK, as I already have Canon lenses my personal choice would be the 50D. If someone in your family already has a Canon or a Nikon (or Pentax or Sony/Minolta) it's easy to get a camera of the same brand so you can use each other's accessories.

There is no reason why you should choose a 40D over a 50D, apart from the price maybe; but the difference is not really extreme so I'd get the 50D.

I'd rule out the 40D, there's no competition between it and the 50D/D90.

Between the 50D and D90, it's a difficult choice. They are about the same age (okay, so the D90 is one day younger), albeit neither are exactly what I'd call "cutting edge" either.

Where the 50D wins is in the build quality department, it's constructed out of a sturdy mag-alloy shell; much more durable than the D90's plastic. It also has more megapixels for large prints, a faster burst rate, plus a faster max shutter speed. However, the D90 is by no means a slouch. On the Nikon side you'll get better high ISO performance, a superior viewfinder, better AF, much greater dynamic range, plus a video mode (it's 720p only, but at least it's an option).

They're really similar cameras, the D90 may have slightly better IQ (this could be my Nikon fanboy mentality speaking though), however the 50D has a few more MPs. the 50D has a better build, but the D90 has a video mode. What it will really come down to is feel or ergonomics, and the price. Go into your local camera store and try each body out, or if they don't have a D90 and 50D, just try a similar Nikon and Canon out. If you don't have a preference, let price be the deciding factor. If they're the same, flip a coin they're both excellent cameras, and in the hands of a good photographer will produce stupendous images.

Still the 50D has only three more megapixels - it is a difference but not a really huge one. EOS 50D: 4.752 × 3.168Nikon D90: 4.288 × 2.848 And as you even considered a 40D (3.888 × 2.592) I don't think it will be a deal breaker.

Well, except for the video, the 50D's the better camera. On 100% crops, the D90 may have a small edge, but when printed on the same size, the 50D's noise will be less. Also, the D90 has only 1 cross-type sensor (though10 other normal af-points) and the 50D has 9 cross-type sensors -which are faster. The viewfinder is the same, the D90 has grid lines which you can switch on or off though.

Debatable but IQ is much more down to the lens you use. It's a fairly extreme comparison but the 40D with mid-range level glass in front of it will almost certainly give you better sharpness than the D90 with a cheap, soft lens.

In the real world, contemporary bodies tend to have marginal differences in terms of IQ when all else is equal.

Instead of fretting about which is "the best" or which wins the Top Trumps statistics, perhaps you should focus on which works best for you as an individual?

Instead of fretting about which is "the best" or which wins the Top Trumps statistics, perhaps you should focus on which works best for you as an individual?

Not going to know that without buying one!

I can't say I agree with you on that.

YMMV but handling the camera itself and scrolling through its menu can really influence your decision. I pretty much cut my choices down to the Canon EOS 550D and the Nikon D5000. I knew the Top Trumps in terms of the advantages they had over each other which didn't settle anything but when I handled the 550D and browsed its menu and did the same with the Nikon, I was satisfied that the 550D would be the better choice for me on the grounds that I preferred its ergonomics and would therefore use it more, thereby improving my skills with practice.

Finding the 40D in stores will probably be difficult but you shouldn't have too much trouble finding the 50D or the D90 at an independent photography/CE store.

handling the camera itself and scrolling through its menu can really influence your decision.

Totally agree, go into a camera store and try out a 40D, 50D or D90 (or their modern equivalents if you can't find them), and see which one works best for you in terms of handling and feel. I chose the D7000 because it would be compatible with my selection of old AI-S Nikkor lenses, but if the 60D had felt better in my hands, I would've saved a few bucks and gone Canon.

If you st ill can't make up your mind in store, find a place with a good return policy, buy them both, and then make your decision based on after being able to use them in the wild for a bit. Make your decision, and return the one you like less (or better yet, return them both and get it through Camera Labs' Amazon link! ) There are also plenty of camera rental services if you'd prefer that, so there are plenty of options.